The goal of this proposal is to continue development of a small, lightweight programmable battery operated processor, which can detect neural action potentials (spikes) for chronic recording studies. We propose to develop two new devices: a 16-channel processor and a 4-channel miniaturized processor. We also propose to develop a wireless network between the processors and sensors including, accelerometers, temperature sensors, and microphones. The 16-channel device will allow chronic multichannel recordings from unrestrained animals and open up new avenues of research in neural function in freely behaving animals. The miniature device will allow recordings from small animals, such as rats. A comprehensive software package for programming the processor, downloading and analyzing spike data and continuous data will also be developed. Finally, the devices and sensors will be tested in the lobster to test its ability to be used under freely behaving conditions. These devcies will also be useful for continuous recordings of low data rate signals, such as field potentials, ECG's, EEG's, EMG's and thus be useful to both researchers and clinicians. They will also be useful for the development of neural prosthetics, where custom digital signal processing circuits can be programmed and tested on the processor. PROPOSED COMMERCIAL APPLICATION: The proposed project is to develop a processor to detect and record neural action potentials and record slow bioelectric signals such as EEGs, EMGs, and ECGs from unrestrained animals for research applications. There are broad applications for such a processor for recording these signals for both research and clinical markets. The device will also be useful as a research tool for neural prostheses (e.g. in controlling robotic arms based on neural activity and processing signals for cochlear implants). There are also many clinical applications, such as a digital Holter (heart) monitor to record and detect irregular heart beats.